CI: Add Python 3.11 to test matrix

Author: ghisvail

.github/workflows/testpydra.yml

@@ -16,7 +16,7 @@ jobs:
     strategy:
       matrix:
         os: [macos-latest, ubuntu-latest, windows-latest]
-        python-version: [3.7, 3.8, 3.9, "3.10"]
+        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11']
       fail-fast: false
     runs-on: ${{ matrix.os }}